no bulgarian passport holders need no visa
If you are form Australia than no need to passport to travel < a href=http://www.cruiseeasy.com.au/>cruise Australia.
If you are a US citizen, you will need both a valid US passport and an Australian ETA visa to travel to Australia.
No
No, but you do need a valid passport.
You'll need a US PASSPORT to return to the US.
Yes, anytime you leave the country you do.
You have to been in Bulgaria and asked the town console for a passport .
No. You only need to use a passport if you are traveling overseas. This doesn't mean that it's free to travel from state to state.
A passport, a visa, possibly vaccinations depending on where you are coming from, and no evil intentions.
You need a passport
Yes, and it must have at least 6 months validity left.